<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Test Page</title>
    <script src="https://cdn.jsdelivr.net/npm/vue@2.6.10/dist/vue.js"></script>
</head>
<body>
    <h1 id="app">{{ message }}</h1>
</body>
</html>
<script>
var app = new Vue({
  el: '#app',
  data: {
    message: '404 not found'
  }
})
</script>